1. Technical Field
The present invention relates to a coordinate input device such as a touch panel and a display device.
2. Related Art
Recently, as a small information electronic apparatus such as a personal digital assistant (PDA) or a notebook type personal computer come into wide use, a display device including a touch panel for performing an input operation by touching an object such as a finger or a pen on a display screen is widely used. In such a touch panel, a method of detecting a touch position of a finger includes an electrostatic capacity method. The electrostatic capacity method indicates a method of flowing weak current by electrostatic capacity formed by touching a finger of a person on a display surface and detecting the touch position from the amount of current. Here, in the electrostatic capacity method, since a planar detection electrode and a dielectric film laminated on the detection electrode are used, the electrostatic capacity is formed by touching the finger on the dielectric film.
In the touch panel using the electrostatic capacity method, as a method of detecting a two-dimensional coordinate, there is a method of obtaining an X coordinate and a Y coordinate using a detection electrode for obtaining the X coordinate and a detection electrode for obtaining the Y electrode (for example, see JP-A-2000-81610, JP-A-1993-19233 and U.S. Pat. No. 6,288,707).
However, even in the known coordinate input device, the following problems occur. That is, in order to ensure an electric insulating state, two-dimensional intersection is realized by forming the detection electrode for obtaining the X coordinate and the detection electrode for obtaining the Y coordinate on different layers via an insulating film or forming wires on two different layers via an insulating film. Accordingly, the detection electrode or the wires need to be formed on the upper and lower layers of the insulating film and thus at least the three-layer structure is obtained. Therefore, a manufacturing process becomes complicated.